[Effects of tacrolimus and cyclosporine on albumin secretion in cultured human hepatocyte]

To investigate the effects of inflammation cytokines, (FK506) and cyclosporine (CSA) on albumin secretion, and the effects of FK506 and CSA on the IL-6 induced suppression of albumin synthesis in cultured human hepatocytes.

Human hepatoma cell lines (HepG2 cells) were separately cultured with IL-6, IL-2 and IL-10 (0 approximately 10 microg/L) and FK506, CSA (0 approximately 100 microg/L) for 48 h. In another experiment, HepG2 cells were stimulated with different doses of FK506 and CSA (0 approximately 10 microg/L) in the presence of IL-6 (5 microg/L) for 48 h. Albumin levels in the supernatant of all groups were measured by radioimmunoassay (RIA). The concentration of LDH secreted by cells stimulated with FK506 and CSA were detected with spectrophotometry.

For cultured HepG2 cells, IL-6 significantly decreased albumin levels in a dose-dependent manner (P <0.01), and the maximal inhibition occurred at 5 microg/L. CSA mildly decreased albumin levels and a significant reduction in albumin production was first visible at 10 microg/ L (P <0.05). In contrast, IL-2, IL-10 and FK506 did not significantly influence albumin pro- duction (P > 0.05). FK506 obviously decreased LDH levels in the supernatant (P < 0.05) and attenuated IL-6 induced suppression of albumin synthesis (P < 0.01). But CSA slightly increased LDH concentration and could not block the IL-6 induced decrease of albumin synthesis (P > 0.05).

IL-6 but not IL-2 and IL-10 suppressed the production of hepatic albumin in vitro. FK506 protected against the suppression of hepatic albumin synthesis caused by IL-6, suggesting its potential role in improving hypoalbuminaemia in immune glomerulonephritis.